A novel low-cost power factor correction cell (PFCC), inserting between rectifier/capacitor input and a variety of DC/DC converters of the off-line switching power supplies, is proposed. By adding this cell, the conventional off-line switching power supplies can easily meet with IEC-1000-3-2 Class A or Class D. The DC bus voltage on the bulk capacitor can be kept lower than 400 V, even at high line and light load condition, in universal line voltage applications. Moreover, the output voltage ripple of the DC/DC converters can be reduced because of no low-frequency components. Experimental results, obtained on a 130 W (16 V/8 A) prototype PFC circuit with flyback DC/DC converter, are given to verify the circuit characteristics.